Electric-arc lamp.



No. 637,448. I Patented Nov. 2|, 1899. W. J. DAVY &. G. THOMAS-DAVIES.

ELECTRIC ABC LAMP.

(Application fil d Oct 7, 189?.)

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f Invento Patented Nov. 2|,l899. W. J. DAVY & G. THOMAS-DAVIES.

ELECTRIC ARC LAMP.

(Application filed Oct. 7, 1897.)

(No Model.)

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Patented Nov. 2|, I899. W. J. DAVY & G. THOMAS-DAVIES.

ELECTRIC ARC LAMP.

(Application filed Oct. 7, 1897.)

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UNITED STATES PATENT OFFICE.

\VILLIAM J. DAVY AND GEORGE THOMAS-DAVIES, OF LONDON, ENGLANlj.

ELECTRIC-ARC LAM F.

SPECIFICATION forming part of Letters Patent No. 637,448, dated November21, 1899. Application filed OOtOl-Jel' '7, 1897. fierial No. 654,393.(No model.)

To ctZZ whom it may concern:

Be it known that we,WILLIAMJA1\iEs DAVY and GEORGE THOMAS-DAVIES,subjects of the Queen of Great Britain and Ireland, and residents ofRonalds road, Highbury, London, England, have invented certain new andusefulImprovementsin Electric-Arc Lamps; and we do hereby declare thefollowing to be a full, clear, and exact description of the inventionsuch as will enable others skilled in the art to which it appertains tomake and use the same.

This invention forimprovements in electric arc lamps relates moreespecially to lampsin which the arc burns in an inclosed chamber toincrease the length of life of the carbons; and one of the objects ofthis invention is to provide an efficient inclosed alternate or directcurrent arc-lamp. In this lamp a perfect inclosure is obtained withoutthe aid of the outer globe, so that the capacity of the chamber is smalland without the use of a sliding or similar joint through which air andgas can diffuse or pass.

In the accompanying sheets of illustrative drawings, Figure 1 is asectional elevation of an inclosed arc-lamp constructed according tothis invention. Fig. 2 is asection at right angles to Fig. 1. Fig. 3 isa cross-section of the controlling bobbin or solenoid. Figs. 4, 5, and 6are detail views showing the arrangement for securing the inclosingglobe to the lower-carbon holder, which is fixed. Fig. 7 shows themethod of suspending the solenoidcore from the dash-pot. Figs. 8, 9,andlO are details of the brake or controlling gear, and Figs. 11 and 12details of the dash-pot for steadying the mechanism.

The frame of the lamp consists of the central tube CL and of the upperdisk Z), rigidly secured to the tube a. The top of the tube a is closedby a disk a, fitting tightly therein and secured to an ebonite plug afixed in the upper end of the tube a. The ornamental casing c of thelamp and the suspending-piece c are secured to the tube a by the bolt 0passing through c, c, and a Below the up per disk I) is a lower disk at,secured to the disk Z) by bolts 02. A casing cis clamped between thedisks and d, and thus forms, with the disks 1) and d, an inclosedchamber of the regulating mechanism. The bottom yoke j is carried fromthe lower disk 61 by the yokerods f.

The regulatingbobbin 9 is wound on a former and between two flanges g,fixed on a tube 9 that is forced against the upper disk I) by thespring-cap g sliding on the frametube a. Thin longitudinal strips 9 ofiron, are placed around this bobbin and forced into shape and secured inposition by the bindingwires The regulatingcoil thus also forms animpedance-coil.

The tubular core it, made of iron strips for alternate-current lamps andiron tube for direct-currentlamps, slides free Within the tube g and issuspended from the dash-pot t' by the side links 72. and bolt 7L2,working in slots at in the frame-tube a. The core h is connected to thebrake or regulating mechanisms by the flexible cords h 77/4.

The upper-carbon holder Z slides in the frame-tube a and is connected bythe flexible conducting-wire Z to the binding-screw Z in one of the sidelinks h. The upper carbon m passes between two jaws n n, fixed,respectively, between the pairs of links n n and 97, 91 connectedtogether at their free ends. The links 71 are pivoted together at theirmeeting ends and at theirouter ends are connected together by the cords71 passing through a loose sleeve 71. to one side of the end of thetubular core h, and the links a n by similar cords h passing through asimilar sleeve 72, to the other side of the end of the core h. The cords71 7t4 can be adjusted by sliding the sleeves h ll on the cords andfixing them by means of set-screws 7L7. The jaws normally rest on thestop-plate M. The sleeves can be dispensed with,the cords being simplysewed or otherwise secured. The pivots are extended outward and guidedin slots in the fixed brackets M. The object of the slotted brackets isto prevent the brake from moving out of its position when insertingcarbons.

The lowercarbon holder 0 screws or fits into the lower end of theinclosing transparent bell p, and the whole rests on a spring 0, fittingin a recess or hole in the stud o screwing into a cross-bar f fitting innotches or trunnions in the bottom yoke f. The crosspiece f can belifted out of the yokef. The

stud 0 also carries the nut 0 for securing the usual globe q inposition.

At the top of the lamp is the usual resistance-coil a", wound on abobbin and connected in series with the series-controlling bobbin of thelamp.

The dash-pot t' is connected by the links h to the core h. The piston t"of the dash-pot is fixed to the frame-tube a by the pin 4?. The dash-pott' can thus move between the piston t" and the closing disk to of thetube (6. This dash-pot acts as another piston or plunger in the dash-potformed by the tube a and the disk at.

The action of the lamp is as follows: The current enters the lamp andpasses through the resistance-coil r, thence to the framedisk b andframe-tube a, and partly through the tube a and partly through theflexible conductor Z to the uppercarbon holder, through the carbons tothe lowercarbon holder, and by the conductor Z to the insulatedbinding-screw Z, thence through the regulatingsolenoid to the negativeterminal. The carbons being in contact, the upper carbon resting on thelower by its own weight, on the passage of the current through thesolenoid the core h and consequently the cords 71. h are drawn up andfirst raise the links a n n 72 off the stop-plate and then cause thejaws to grip the carbon and raise it and strike the arc. As the arclengthens, due to the burning away gradually, the grip device is loweredonto the stop-plate and the jaws relax their hold on the carbon and acontinuous and steady feed is obtained by the upper carbon slowlydescending through the jaws. The spaces open to the are are thus thechamber inclosed by the bell p, the chamber inclosed by the casing e,the frame-tube a, and the solenoid-tube g Any excessive pressure ofgases accumulating escapes through the spring-cap g or the mouth of thebell, the spring 0 acting as relief.

To renew the carbons, the screw 0 is slackened to remove the globe g.The stud o is then unscrewed out of the cross-piece f until thecross-piece can be raised out of its recesses or trunnion-bearin gs inthe yoke f and then removed, with the bell and lower-carbon holder,through the yoke f, the top carbon and holder following by its weight.The top carbon is then removed and inserted in the lower-carbon holderand a fresh carbon placed in the upper holder, when the bell and lowercarbon are placed in position, forcing upward the upper-carbon holder toits upper position. The upper edge of the bell rests against an asbestoswasher s, and by gently screwing up the stud o the bell is forcedagainst the asbestos, the spring 0 allowing for expansion andcontraction and the like. The globe q is then replaced.

What we claim, and desire to secure by Letters Patent, is-

1. The construction and arrangement of the frame of the inclosedarc-lamp consisting of the central frame-tube, the solenoid-tube, theupper disk secured thereto, the lower disk bolted to the upper disk, theinclosing ring inclosing the space between the two disks and the loweryoke secured by yoke-rods to the lower disk and the glass bell the wholeforming a perfectly-closed chamber, substantially as described.

2. The construction and arrangement of the regulating devices consistingof the grip device, the frame-tube, the uppercarbon holder sliding inthe frame-tube, the solenoid core surrounding the frame-tube andconnected to the grip device, the solenoid surrounding the solenoidcore,the dash-pot situated in the upper end of the frame-tube, and thecross-bar working in slots in the frame-tube and connected to thedash-pot and to the solenoid-core.

3. The means for securing the inclosing bell in position consisting ofthe bottom yoke supported from the frame of the lamp, the crossbarfitting in notches in the yoke, the stud screwing into the cross-bar,the lower-carbon holder secured to the transparent bell, and a springWithin the stud and on which the carbon-holder rests.

In testimony whereof we have affixed our signatures in presence of twowitnesses.

WILLIAM J. DAVY. GEORGE THOMAS-DAVIES.

\Vitnesses:

ALBERT JONES, 1 CHRISTOPHER S. PARKER.

